Hi Helen,

thanks for your suggestions.

> Don't use the Params[] array, you lose some essential stuff
> if you do and
> in some queries it can get scrambled. Always use ParamByName.

Thanks for the tip. I'll always use ParamByName. Unfortunately, in this case
ParamByName does not help, either.

> You get EOF if the dataset is empty. You get BOF as well.

Sure, I get both Eof and Bof - the result set is empty, but it shouldn't be
because there is data in the table satisfying the WHERE A IS NULL condition,
as explained in the original posting. SELECT * FROM TEST WHERE A IS NULL
works of course as expected.

I tried setting FieldByName('A').BlankIsNull := True; and also
ParamByName('A').BlankIsNull := True;
with the same results. The only way around I can see so far is to
reconstruct the SQL.Text property to use IS NULL explicitly instead of
parameters.

Cheers,
TOndrej